NASA-TV will carry the briefing live from Johnson Space Center in Houston.

The agreement, according to NASA, "expands on the successful partnership between the agencies on the International Space Station and other activities," and "ensures continued international collaboration as humans explore new frontiers in the solar system."

The Orion Service Module (SM) is not presently a planned part of crew capsule tests, beginning in 2014. Exploration Test Mission-1 (EMT-1) will be lofted into high-Earth orbit on a Delta-IV heavy booster. NASA's next "man-rated" booster, the Space Launch System (SLS), may not be ready before 2017.

The news conference participants will include Bill Gerstenmaier, NASA associate administrator for Human Exploration and Operations; Thomas Reiter, ESA director of Human Spaceflight and Operations; Mark Geyer, Orion Program manager and Bernardo Patti, ESA manager of International Space Station operations.

Presently scratched into "out years" of NASA funding are proposed manned flights of the Orion-MPV system ferrying crews to the International Space Station as early as 2017, with a possible return to lunar orbit, a Hubble Space Telescope servicing mission and long duration flights in the decade following.

The Orion system is all that remains of the crewed segment of the cancelled Constellation program, whose trailing legacy includes the Lunar Reconnaissance Orbiter (LRO), the now-completed GRAIL lunar gravity mapping mission and the Lunar Atmosphere and Dust Environment Explorer (LADEE) scheduled for launch later this year.